Surgical wires and cables are used in a variety of medical procedures, for example reconstructive spine surgery such as fusions, spine trauma surgery, total hip arthroplasty, fracture fixation, open heart surgery for closure of the sternum, oral/facial surgery to fix mandibular fractures and other trauma surgery. Often, surgical cables and wires are used to encircle bones to hold them together for healing if broken or for fusion in the case of some types of spinal surgery. For purposes of this application, "cable" includes monofilament and single strand wire along with multifilament and multistrand cable and wire ropes.
Problems sometime occur with placing the correct tension in surgical cables during installation. Current systems for attaching surgical cables to selected portions of a patient's body have experienced problems with the cables being applied too tightly and creating a vascular necrosis of the bone around which the cables are wrapped. At the same time, surgical cables must be tight enough to achieve the desired mechanical fixation. Many conventional systems are difficult to manipulate and surgeons have experienced problems in properly positioning the cable while at the same time applying the desired tension. Many currently available products do not provide direct feedback to the surgeon concerning the amount of tension being applied to the cable. The mechanical advantage incorporated into current products effectively blocks tactile sensing and control of the amount of applied tension.
Examples of apparatus and equipment used to install cables and wires during surgical and other medical procedures are shown in U.S. Pat. No. 4,050,464 entitled "Surgical Cable Tensioning Instrument"; U.S. Pat. No. 4,587,693 entitled "Instrument for Positioning a Cerclage Fixation Device Around Fractured Bone Parts"; U.S. Pat. No. 4,966,600 entitled "Surgical Severance Method"; and U.S. Pat. No. 5,057,113 entitled "Device for Tensioning Traction Wires in Orthopedic Surgery". The above-referenced patents are incorporated by reference for all purposes within this Application.